Have you ever heard uracil?

　　Uracil is one of five nitrogenous bases that attach to nucleotides found within cells. A nucleotide is made up of a five carbon sugar, pentose sugar, with a phosphate group and base attached. Nucleotides are the building blocks for two important nucleic acids – deoxyribonucleic acid, DNA, and ribonucleic acid, RNA. The other four bases are cytosine,guanine, adenine and thymine.


Uracil,66-22-8


　　The five bases are broken up into two groups based on their structure. The pyrimidine bases are made up of a single ring of atoms and include cytosine, thymine and uracil. The purine bases have a double ring of atoms and include adenine and guanine. They are called nitrogenous bases as they contain nitrogen and carbon atoms in the ring(s).
　　Uracil is a common and naturally occurring pyrimidine derivative.Originally discovered in 1900, it was isolated by hydrolysis of yeast nuclein that was found in bovine thymus and spleen, herring sperm, and wheat germ.It is a planar, unsaturated compound that has the ability to absorb light.
　　1.Reactions
　　Uracil readily undergoes regular reactions including oxidation, nitration, and alkylation. While in the presence of phenol (PhOH) and sodium hypochlorite (NaOCl), uracil can be visualized in the blue region of UV light.Uracil also has the capability to react with elemental halogens because of the presence of more than one strongly electron donating group.
　　Uracil readily undergoes addition to ribose sugars and phosphates to partake in synthesis and further reactions in the body. Uracil becomes uridine,uridine monophosphate (UMP), uridine diphosphate (UDP), uridine triphosphate (UTP), and uridine diphosphate glucose (UDP-glucose). Each one of these molecules is synthesized in the body and has specific functions.
　　When uracil reacts with anhydrous hydrazine, a first-order kinetic reaction occurs and the ring of uracil opens up.If the pH of the reaction increases to >10.5, the uracil anion forms, making the reaction go much slower. The same slowing of the reaction occurs if the pH decreases because of the protonation of the hydrazine.The reactivity of uracil is unchanged even if the temperature changes.
　　2.Uses
　　Uracil can be used for drug delivery and as a pharmaceutical. When elemental fluorine is reacted with uracil, 5-fluorouracil is produced. 5-Fluorouracil is an anticancer drug (antimetabolite) used to masquerade as uracil during the nucleic acid replication process.Because 5-Fluorouracil is similar in shape to, but does not perform the same chemistry as, uracil, the drug inhibits RNA replication enzymes, thereby eliminating RNA synthesis and stopping the growth of cancerous cells. Uracil can also be used in the synthesis of caffeine
　　Uracil's use in the body is to help carry out the synthesis of many enzymes necessary for cell function through bonding with riboses and phosphates.Uracil serves asallosteric regulator and coenzyme for reactions in the human body and in plants.UMP controls the activity of carbamoyl phosphate synthetase and aspartate transcarbamoylase in plants, while UDP and UTP requlate CPSase II activity in animals. UDP-glucose regulates the conversion of glucose to galactose in the liver and other tissues in the process of carbohydrate metabolism.Uracil is also involved in the biosynthesis of polysaccharides and the transportation of sugars contain ingaldehydes.
　　It can also increase the risk for cancer in cases in which the body is extremely deficient in folate.The deficiency in folate leads to increased ratio of deoxy uracil mono phosphates (dUMP)/deoxy thymine mono phosphates (dTMP) and uracil misincorporation into DNA and eventually low production of DNA.
　　Uracil can be used to determine microbial contamination of tomatoes. The presence of uracil is an indication of lactic acid bacteria contamination in the fruit.Uracil derivatives containing a diazine ring are used in pesticides.Uracil derivatives are more often used as anti photo synthetic herbicides, destroying weeds in cotton,sugar beet, turnips, soya, peas, sunflower crops, vineyards, berry plantations, and orchards.
　　In yeast, uracil concentrations are inversely proportional to uracil permease.